Container and treating apparatus for sour crude oils



Patented Mar. 24, 1953 2,632,562 CONTAINER;AND TREATING Are RA'fiis FOR-SOUR CRUDE OILS- Clarence-Hi'Dragert; Dallas; Tex.-

No Drawing.- ApplicationJune 9, 1948}. Serial N0. 32,050

3 Claims;

Thisinventioii relates to improvedme'thods for storing andtreating-sour crudeoils and for providing improved tanks and apparatus forthis" purpose, r

Such sour crude oils contain varying amounts of sulphu compounds and. varyingamounts of emulsified water, and, under'the usual conditions of storage in steel tanks, rapidly attack'the metal of such containers bycorrosion. Even the upper portions of such containers, whichare not in directcontact with the liquid oil, are attacked by the'fumes of the contents, so that they are rendered unfit in a relatively-short time and require frequent replacement, thus adding greatly to the annoyance andcostof properly storing and treating' the oils of this grade. It is not unusual, under intensive use, that heavy metal tanks and piping require-replacement within as short atime as thirty days, andthey seldom remain fit for service beyond a fewmon-ths. r i

, Theconditions are especiallysevere where oil treatmentis necessary. If the oil comes from the ground as an emulsion with water, such oil must often be treated to break-the emulsion. This is done with what is known as an oil treater. Such treat'ers are tall tanks which contain a heating unit which heats the contents to about 140 F;

While the mere storing of the'sulphur contain:

ing sour crude-oilsis destructive of the containers in a relatively short time, the corrosion proceeds at aneven'more rapid rate in this treating process.

It has long been aproblem forithe operator, in thisparticular field to find satisfactory meansfor coatingithe inner surfaces of the drums used for storageand the tanks employed for treating these sour crude oils. Many different oils; paints, cements, and other compositions and devices have been tried as protective means but with little avail.

Thus, steel shells have been made heavier with the possible expectation that, after the corrosion proceeded to a degree, the corrosion crust would itself act as a retardant against further destructive action before the metal was too deeply affected; heavy paint coverings and inner cement shells have been applied; and various forms of rubber coatings have also been tried. But none of these various methods have produced any really efiective economies. The heavier steel took somewhat longer for perforation, but the higher costs cancelled any gain in the longer time for re-installation. oxide, carbonate or sulfate, are soon eaten away and even the inner cement shells crack and fall off, while the rubber coatings blister and peel off very soon. Metallic coating, as by galvanizing,

2 has also f aild in producingany satisfactorysolution of thisproblen'i'i Ordinary paints, containing lead' It has now been discoveredbythe-applicanfi that the life ofthe' steel storage'drurns and'treat ing tanksandthe' like; can be considerably" pro longed f or practical periods" and "to such a; degree as to result in substantial economies for this industry both in thema'terials and in'the expense for re installatioris; This improvement is" at taiiied by theapplication'of an'a'dhesivecoating carrying metallic lead powder in sufiicientcon=- centratio'n" so as" to" afford substantially uniform deposits of the lead metali With such a protective lead-powder coating; containers have been inverylprolongedf operation and some such are'still'in active use.without'tdiscoverable depreciation,

The compositions of the coating agentsiwhich" are useful for adaptation't'o the practice'of my invention herein,.comp'rise fihelyjdividedlead metal; dispersed "in' various liquid media such as'arege'nerally employed for protective coatings by themselves or which serve as vehicles for carrying" ordinary paint pigments, such as lead carbonate, oxide, and sulfate; Various useful types' 'of'vehicles as are illustrated herein mayjbe modified considerably both'as td'c'o'mp'onents and a to their relative proportions, as a matter of choicelfor. adaptation .to special conditions. The important andlcontrolling constituent in all"such comp'o'si= tions is thefinely divided lead metal, which has beenlfound to' be the practicalprotective agent against'this destructive'sour crude oilliq'u'idan'd its fumes.

The ch'oicea's to carrier composition'maybe determined to a large degree by local'conditions; and the special compositions of' the particular types of'thesour' orudeoil b'eing'treat'ed: I'n general; the guiding'principleis 'to' provide mea'nsfor good binding, distribution, dispersion and suspension, and the carrying and suspending medium should also be substantially inert to the action of the sulphur compounds contained in the oil.

A serviceable coating composition which has proved effective is prepared with pounds of esterified rosin 25 gallons of China-wood oil 300 pounds of thinner After cooking in the conventional manner, about 14 pounds of finely divided lead powder are added per gallon of liquid with active stirring until the metal is well dispersed throughout. The mixture is then ready for application to the surfaces to be treated.

The China-wood oil has been serviceably substituted by other oils, such as oiticica, linseed, dehydrated castor oil, perilla and soya bean oil, also fish oil.

Similarly, substitution has been made for the esterified rosin, in the form of cumar resin derived from coal tar, pure and modified phenolic resins, maleic acid type resins, etc.

Another type of composition which has been employed successfully, embraces the use of alkyd resins, such as are derived by the action of polybasic acid on polyhydric alcohols. Still another type of vehicle is that which has been obtained by using the polymerized products from vinyl acetate, vinyl chloride, polystyrene, chlorinated rubber, etc. Such polymers, when plasticized and formulated with some hard resin to efiect adhesion, serve well as covering agents.

When used along, or with the usual lead paint pigments, such coatings do not protect the interiors of vessels containing the sour crude oils, from the ravages of corrosion. However, when any of these several types of coating media are used as carriers for the lead powder as disclosed herein, there is provided a coating which serves definitely for protection against such corrosion.

The viscosity may also be suitably controlled for adaptation to brushing or spraying within practical limits, but with due regard to the proper and even dispersion and suspension of the lead powder.

The amount of lead powder in such mixtures is preferably from about 12 to 14 pounds of lead to the gallon of liquid. For convenience in handling and application this amount may optionally also be varied within practical limits. Obviously, when less of metal powder is included in a given batch, this may require the application of more coats for effective coverage and hiding of the surfaces to be protected.

The metallic lead ingredient may also be employed in varying degrees of fineness from as much as about 200 mesh to a practically impalpable powder, depending upon the service expected, the character of the surfaces to be covered, the number of coats deemed desirable, and the method of application as by brushing for instance or by spraying. Obviously, the finer the lead powder the better the suspension and dispersion. Depending on these variable factors, also a greater or less number of coats may be superimposed so as to attain satisfactory and practical over-all coverage of the surfaces to be coated, with the lead.

It is highly desirable that the lead metal powder, as used in preparing the mixture, should be freshly prepared or should be protected against air and moisture so as to avoid any substantial chemical change in the metal, as by oxi- 2,632,562 W h A dation. Any considerable amount of oxidation is detrimental.

It is a noteworthy fact, that these same leadmetal coatings herein disclosed have not been found effective as protective agents against corrosion of metallic exteriors of plant equipment and apparatus in chemical laboratories, which are exposed to the fumes of sulphuric acid and hydrogen sulfide. Yet, when these same compositions which have thus been found ineffective on such exteriors are coated upon the interiors of the sour crude containers, definite protection is afforded by such coatings for prolonged periods.

I claim:

1. The process of storing and treating sour crude oils which comprises introducing such oils into a container whose body is composed of ferrous material which reacts destructively with the acidic and sulfurous constituent of these oils, but which has the inner surfaces substantially evenly covered with a coating comprising finely comminuted lead metal.

2. The process of storing and treating sour crude oils which comprises introducing such oils into a container whose body is composed of ferrous material which reacts, destructively with the acidic and sulfurous constituents of these oils, but which has the inner surfaces substantially evenly covered with a coating comprising finely comminuted lead metal, substantially free from oxide.

3. The process of storing and treating sour crude oils which comprises introducing such oils into a container whose body is composed of ferrous material which reacts destructively with the acidic and sulfurous constituents of these oils, but which has the inner surfaces substantially evenly covered with a coating comprising finely comminuted lead metal, substantially free from oxide, and binding material substantially inert to such crude oil acids and sulfur compounds.

CLARENCE H. DRAGERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,210,375 Decker Dec. 26, 1916 1,717,140' Brandenberger June 11, 1929 1,911,696 Lerio, Jr May 30, 1933 1,961,936 Mallinkrodt, Jr., et a1. June 5, 1934 2,041,392 Bean May 19, 1936 2,245,745 Ball June 17, 1941 2,346,714 Wobbe Apr. 18, 1944 

3. THE PROCESS OF STORING AND TREATING SOUR CRUDE OILS WHICH COMPRISES INTRODUCING SUCH OILS INTO A CONTAINER WHOSE BODY IS COMPOSED OF FERROUS MATERIAL WHICH REACTS DESTRUCTIVELY WITH THE ACIDIC AND SULFUROUS CONSTITUTENTS OF THESE OILS, BUT WHICH HAS THE INNER SURFACES SUBSTANTIALLY EVENLY COVERED WITH A COATING COMPRISING FINELY COMMINUTED LEAD METAL, SUBSTANTIALLY FREE FROM OXIDE, AND BINDING MATERIAL SUBSTANTIALLY INERT TO SUCH CRUDE OIL ACIDS AND SULFUR COMPOUNDS. 